Leafs curled down on the margins !!!

Hi guys , i was wondering why this happens, the color of leafs are normal but they just curled down symetrical arround the margins ,is it normal? if someone knows , any comment is apreciated.
i have to mention that i water them every day like 400cc for a 4 litre pot of soil. and no water comes out of drainage(the hole at bottom) . could it be because of over watering???
or lack of ventilation ?? light overdose ??
Thank you in advance

My english sucks , LEAVES , sorry about that.
the very tip of those are burned accidentaly touched the lamp , but the other leavs which are far from lamp curled as well.